EN
Costs’ calculation problems in economics of agriculture were repeatedly discussed in the past. Direct and indirect costs are of an essential importance while planning and decision making. Considering decision making process related to future tasks e.g. performance of plant protection treatments, the information on expected costs and profits is required. Because of this, there is an urgent need of introducing a supplementary cost classification allowing to separate the costs relevant to decision making process. Costs of plant protection – a production activity involved in agrophages’ controlling, presents a part of economic costs. In calculating plant protection treatment costs, typical rules for economics of agriculture are used. Costs of plant protection treatments differ from other costs in agricultural production due to a different influence on yield. Plant protection treatments do not affect the increase of yield directly but prevent from losses caused by agrophages. Plant protection costs can be divided into three groups: costs of plant protection products, costs of water, costs of plant protection product application.